ML060950427

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Letter, SG Inspections Report
ML060950427
Person / Time
Site: South Texas STP Nuclear Operating Company icon.png
Issue date: 04/20/2006
From: Thadani M
Plant Licensing Branch III-2
To: Sheppard J
South Texas
Thadani M
References
TAC MC8622
Download: ML060950427 (6)


Text

April 20, 2006 Mr. James J. Sheppard President and Chief Executive Officer STP Nuclear Operating Company South Texas Project Electric Generating Station P. O. Box 289 Wadsworth, TX 77483

SUBJECT:

SOUTH TEXAS PROJECT, UNIT 1 - RE: EVALUATION OF THE 2005 STEAM GENERATOR TUBE INSPECTIONS (TAC NO. MC8622)

Dear Mr. Sheppard:

By letters dated October 12, 2005, and February 28, 2006, STP Nuclear Operating Company, the licensee for South Texas Project (STP), submitted information summarizing the results of its 2005 steam generator tube inspections at STP Unit 1.

The 2005 tube inspections were performed during refueling outage 12. In addition to these reports, the U.S. Nuclear Regulatory Commission (NRC) staff summarized additional information in a letter dated May 27, 2005. The additional summarized information related to the 2005 steam generator tube inspections of foreign objects found in the steam generators.

The NRC staff has completed its review of these reports and concludes that the licensee provided the information required by its technical specifications and that no additional follow-up is required at this time. The staffs evaluation of the licensees reports is enclosed.

If you have any questions concerning the enclosed NRC staffs evaluation, please contact me at (301) 415-1476.

This completes our effort under TAC No. MC8622.

Sincerely,

/RA/

Mohan C. Thadani, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No.: 50-498

Enclosure:

Summary of Staffs Evaluation cc w/encl: See next page

April 20, 2006 Mr. James J. Sheppard President and Chief Executive Officer STP Nuclear Operating Company South Texas Project Electric Generating Station P. O. Box 289 Wadsworth, TX 77483

SUBJECT:

SOUTH TEXAS PROJECT, UNIT 1 - RE: EVALUATION OF THE 2005 STEAM GENERATOR TUBE INSPECTIONS (TAC NO. MC8622)

Dear Mr. Sheppard:

By letters dated October 12, 2005, and February 28, 2006, STP Nuclear Operating Company, the licensee for South Texas Project (STP), submitted information summarizing the results of its 2005 steam generator tube inspections at STP Unit 1.

The 2005 tube inspections were performed during refueling outage 12. In addition to these reports, the U.S. Nuclear Regulatory Commission (NRC) staff summarized additional information in a letter dated May 27, 2005. The additional summarized information related to the 2005 steam generator tube inspections of foreign objects found in the steam generators.

The NRC staff has completed its review of these reports and concludes that the licensee provided the information required by its technical specifications and that no additional follow-up is required at this time. The staffs evaluation of the licensees reports is enclosed.

If you have any questions concerning the enclosed NRC staffs evaluation, please contact me at (301) 415-1476.

This completes our effort under TAC No. MC8622.

Sincerely,

/RA/

Mohan C. Thadani, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No.: 50-498

Enclosure:

Summary of Staffs Evaluation cc w/encl: See next page DISTRIBUTION PUBLIC RidsNrrDorlLplg KKarwoski LPLIV Reading RidsNrrPMMThadani RidsOgcRp RidsNrrLADJohnson RidsAcrsAcnwMailCenter RidsRgn4MailCenter ACCESSION NO:

  • No significant change in the SE input OFFICE NRR/LPL4/PM NRR/LPL4/LA CSGB/BC (A)

NRR/LPL4/BC NAME MThadani DJohnson EMurphy*

DTerao DATE 4/18/06 4/14/06 03/10/2006 4/20/06 OFFICIAL RECORD COPY

SUMMARY

OF STAFFS EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION 2005 STEAM GENERATOR TUBE INSPECTIONS STP NUCLEAR OPERATING COMPANY SOUTH TEXAS PROJECT, UNIT 1 DOCKET NO. 50-498 By letters dated October 12, 2005 ( Agencywide Documents Access and Management System (ADAMS) Accession No. ML052910372), and February 28, 2006 (ADAMS Accession No. ML060660182), STP Nuclear Operating Company, the licensee for South Texas Project, Unit 1 (STP), submitted information summarizing the results of its 2005 steam generator (SG) tube inspections at STP.

The 2005 tube inspections were performed during refueling outage (RFO) 12. In addition to these reports, the U.S. Nuclear Regulatory Commission (NRC) staff summarized additional information concerning the 2005 SG tube inspections in a letter dated May 27, 2005 (ADAMS Accession No. ML051510378). The additional summarized information related to the 2005 SG tube inspections of foreign objects found in the SGs.

STP has four recirculating SGs designed and fabricated by the Westinghouse Electric Company. The model Delta 94 SGs were put into service in 2000 during RFO 9. Each SG has 7,585 thermally treated Alloy 690 tubes that have an outside diameter of 0.688-inch and a nominal wall thickness of 0.040-inch. The tubes were hydraulically expanded at each end for the full depth of the tubesheet and are supported by a flow distribution baffle, support plates, and anti-vibration bars.

The licensee provided the scope, extent, methods, and results of their SG tube inspections in the documents referenced above. In addition, the licensee described corrective actions (i.e., tube plugging) taken in response to the inspection findings.

As a result of the review of the reports, the NRC staff has the following comments/observations:

No primary or secondary inspections were performed during the last RFO (RFO 11). For the 2005 RFO 12, sludge lancing and post lancing Foreign Object Search and Retrieval (FOSAR) was scheduled for all four SGs. No primary side tube inspections were scheduled for RFO 12.

Several hundred small wire fragments were identified in SG-D. The wire fragments were attributed to a feedwater cable stabilizer that migrated into SG-D during cycle 11 prior to or during the shutdown for RFO 11.

Based on the FOSAR and visual identification of a wear scar, eddy current inspections were performed in SG-D. The bobbin inspections focused on the straight run of the tubes (i.e., up to the top tube support plate) to look for evidence of foreign material and wear from foreign material. Full length tube inspections were only performed on 56 tubes.

The licensee indicated that the eddy current inspection plan was not intended for surveillance credit. Based on the information provided in the submittal, the staff understood this statement to mean that the inspections were not intended to satisfy the periodic requirement to inspect the tubes; however, the results were used to verify the as-found and continued acceptability of the tubes until the next scheduled tube inspections.

Based on the review of the information provided, the staff concludes that the licensee provided the information required by its technical specifications. In addition, the staff concludes that there are no technical issues that warrant follow-up action at this time, since the inspections appear to be consistent with the objective of detecting potential tube degradation, and the inspection results appear to be consistent with industry operating experience at similarly designed and operated units.

Principal Contributor: K. Karwoski Date: April 20, 2006

February 2006 South Texas Project, Units 1 & 2 cc:

Senior Resident Inspector U.S. Nuclear Regulatory Commission P. O. Box 910 Bay City, TX 77414 C. Kirksey/C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704 Mr. J. J. Nesrsta Mr. R. K. Temple City Public Service Board P. O. Box 1771 San Antonio, TX 78296 INPO Records Center 700 Galleria Parkway Atlanta, GA 30339-3064 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011 Steve Winn Texas Genco, LP 12301 Kurland Drive Houston, TX 77034 Judge, Matagorda County Matagorda County Courthouse 1700 Seventh Street Bay City, TX 77414 A. H. Gutterman, Esq.

Morgan, Lewis & Bockius 1111 Pennsylvania Avenue, NW Washington, DC 20004 E. D. Halpin Vice President Oversight STP Nuclear Operating Company P. O. Box 289 Wadsworth, TX 77483 S. M. Head, Manager, Licensing STP Nuclear Operating Company P. O. Box 289, Mail Code: N5014 Wadsworth, TX 77483 Environmental and Natural Resources Policy Director P. O. Box 12428 Austin, TX 78711-3189 Jon C. Wood Cox, Smith, & Matthews 112 East Pecan, Suite 1800 San Antonio, TX 78205 Director Division of Compliance & Inspection Bureau of Radiation Control Texas Department of State Health Services 1100 West 49th Street Austin, TX 78756 Brian Almon Public Utility Commission William B. Travis Building P. O. Box 13326 1701 North Congress Avenue Austin, TX 78701-3326 Susan M. Jablonski Office of Permitting, Remediation and Registration Texas Commission on Environmental Quality MC-122 P.O. Box 13087 Austin, TX 78711-3087

South Texas Project, Units 1 & 2 cc: Mr. Terry Parks, Chief Inspector Texas Department of Licensing and Regulation Boiler Division P. O. Box 12157 Austin, TX 78711 Mr. Ted Enos 4200 South Hulen Suite 630 Ft. Worth, Texas 76109